Feces color detection device

ABSTRACT

A plurality of color sensing sections are attached to a toilet seat so as to test a health state or a fecal occult blood portion every time by capturing the feces surface color during defecation. Before feces which have been excreted from a body sink into a water-seal portion, the circumference of the feces is optically captured to detect the color of the surface of the feces. By monitoring changes in color, the health state of the defecator is monitored. In particular, by checking the presence/absence of an occult blood portion, the present invention assists in early detection of colorectal cancer and allows a fecal occult blood test to be performed in a hygienic manner without burdening the user.

PRIORITY CLAIM

The present invention claims priority to U.S. application Ser. No.15/319,473, filed Dec. 16, 2016; International Application No.PCT/JP2015/066420, filed Jun. 7, 2015; and Japanese Application No.2014-125844, filed Jun. 18, 2014, the contents of which are hereinincorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a device for detecting the color offeces in the everyday life environment, monitoring the daily healthstate. Particularly, the present invention relates to a device forautomatically detecting occult blood on the feces surface.

BACKGROUND ART

Detecting occult blood in feces is effective at finding colorectaldiseases such as colorectal cancer. Fecal occult blood detection hasbeen employed as a test in a regular medical checkup or a thoroughmedical examination and conducted in many public institutions andmedical institutions for early detection and treatment of colorectalcancer and gastrointestinal diseases. Methods for testing fecal occultblood include chemical methods such as the benzidine method, theorthotolidine method and the guaiac method, the latex agglutinationmethod using latex particles sensitized for an antibody and thechromatography method using a pigment bound on an antibody.

With these fecal occult blood test methods, the user lays sheets ofpaper such as toilet paper in the toilet bowl of a flush toilet tothereafter defecate onto the toilet paper, and the user scrapes thedefecated feces with the fecal sampling pick of the container.

With a western-style toilet, however, feces easily sink into thewater-seal portion of the toilet bowl to be mixed with urine, making itdifficult to sample feces in the toilet bowl, and the hand may touch thefeces when trying to sample the feces with the fecal sampling pick,which is unpleasant and unsanitary.

Moreover, another problem with this method is that it is only possibleto detect an occult blood reaction from positions where the fecalsampling pick scraped, failing to detect occult blood in other portions,resulting in a low 50% detection rate for early-stage colorectal cancer.Also with the low testing frequency, i.e., thorough medical examinationsand regular medical checkups, the death rate for colorectal cancer hasnow risen to the third highest for men and the highest for women, and isstill on the rise. Under such circumstances, there is an increasingdemand for the development of an examination technique that can be usedin everyday life with a high accuracy.

Methods of conducting a fecal occult blood test in a bathroom in ahygienic manner without burdening the user include those of PatentDocument No. 1 and Patent Document No. 2, in which feces excreted from abody are collected before the feces sink into the water-seal portion andthe collected feces are dissolved in a solution, and the solution istransferred to detect the occult blood in the feces-dissolved solutionby an immunoassay. However, these methods have problems such as the badodor when collecting the feces, cleaning of the collecting device, andthe complexity in the maintenance of the detection section.

Another method of conducting a fecal occult blood test in a bathroom isa method in which the defecation gas discharged from the human bodyduring defecation is sucked in and the amine gas contained in the suckeddefecation gas is detected with an amine sensor to detect an occultblood reaction based on the fact that the amount of amine gas increaseswhen there is an occult blood reaction, as in Patent Document No. 3.With this method, the detection accuracy is not high when no defecationgas is discharged during defecation, and it is necessary to have adefecation gas suction part in the vicinity of the feces and it is alsonecessary to clean the tip of the suction part.

On the other hand, Patent Document No. 4 discloses an excrement checkingdevice for capturing the image of an excrement in the toilet bowl anddisplaying the image so that the user can view the image while in aseated position. It captures the image of the inside of the toilet bowlwith a camera, and the user can observe the shape and the color of fecesin a seated position by looking at the monitor screen. This methodmerely allows the user to look at the feces in a seated position and isnot different from looking directly at the feces with naked eyes, andthere is a problem in that the user feels reluctant to observe withnaked eyes every time.

As a method for monitoring the blood, pulse oximeters are well known inthe art that examine the degree of oxygen saturation in the blood. Thisis a method of examining the blood oxygen concentration by using thetransmission intensities of near infrared emissions of differentwavelengths through blood vessels at a finger tip, based on thedifference in absorption spectrum between oxygenated hemoglobin anddeoxygenated hemoglobin. FIG. 1 shows typical absorption coefficientspectra. The vertical axis represents the absorption coefficient, andoxygenated hemoglobin has no absorption at 670 nm and therefore thetransmitted light appears red. Deoxygenated hemoglobin has increasedabsorption, thereby appearing blackish. A pulse oximeter is a method ofexamining the blood oxygen concentration based on transmitted light.

CITATION LIST Patent Literature

Patent Document No. 1: Japanese Laid-Open Patent Publication No.H10-31016

Patent Document No. 2: Japanese Laid-Open Patent Publication No.H10-260182

Patent Document No. 3: Japanese Laid-Open Patent Publication No.2006-132948

Patent Document No. 4: Japanese Laid-Open Patent Publication No.2006-61296

SUMMARY OF INVENTION Technical Problem

With the occult blood test method using a fecal sampling pick, which iscommonly conducted in regular medical checkups and thorough medicalexaminations, the test frequency is as low as one or twice a year.Moreover, if the sampling area to be sampled with the fecal samplingpick is small, the occult blood portion may not be found, resulting in alow detection rate for early-stage colorectal cancer. The method ofsampling the feces with a fecal sampling pick also has a problem ofbeing unsanitary.

Methods in which the detection is performed during defecation in ahousehold toilet bowl have a problem in that the detection is done onlyrarely due to the high maintenance cost of the test, as well as otherproblems: the feces are sampled or the defecation gas is sampled duringdefecation, not only making is necessary to clean the sampling area, butalso complicating the maintenance of the sensor and making it necessaryto provide a means for preventing cross contamination with the subjectimmediately before the test.

The color of feces is sometimes visually observed at home, but it is asensual determination, and it is not possible to observe changes overdays. With the fecal occult blood determination relating to colorectalcancer, one will not notice it until the disease advances to such adegree that it can be recognized with naked eyes, and one may possiblyoverlook early-stage cancer. Beside the occult blood determination,there is a problem in that when the color of feces changes gradually,one may not notice the change until the disease reaches an advancedstage.

Solution to Problem

According to an embodiment of the present invention, a plurality ofcolor cameras are provided on the reverse side portion of the toiletseat so as to capture an image of the feces surface from a plurality ofdirections and observe the color of the feces surface. The data of thefeces color is recorded as time-series data to quantitatively graspchanges in feces color. Particularly, the presence/absence of occultblood, which is highly correlated to colorectal cancer, is determined ona daily basis. The detection accuracy is improved by comparison withother wavelength ranges based on the wavelength spectrum distribution ofoxygenated hemoglobin corresponding to an occult blood reaction.

Advantageous Effects of Invention

With a feces color detection device of the present invention, it ispossible to easily observe changes in the color of the feces surfaceupon defecation on a daily basis, and to detect changes in the color ofthe feces surface, which is correlated to health, particularly, occultblood, in a hygienic manner. With this method of optically detectingoccult blood on the feces surface, cameras are provided on the reverseside of the toilet seat, thereby enabling detection at locations awayfrom the position of defecation, only requiring simple maintenance ofprocessing signals of images captured by the cameras and requiring nospecial reagents, thus facilitating daily monitoring. It also enablesthe feces surface observation from a plurality of directions, making itunlikely to overlook an occult blood reaction on the surface. Anadvantage is that a test can be conducted without the user being awareof it during defecation on a daily basis, leading to early detection ofcolorectal cancer and thus decreasing the death rate.

By using a linear sensor including three color filters of red, blue andgreen as the image sensor in each color camera, it is possible toalleviate the feeling of reluctance of being captured by cameras duringdefecation. This is due to the fact that although a linear sensor canonly capture an image of a stationary object on the same line each time,thus failing to grasp the entire image, it can capture the surfaceconditions of a moving object.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows absorption coefficient spectra of oxygenated hemoglobin anddeoxygenated hemoglobin in blood.

FIG. 2 is a side view of a toilet showing how the feces surface isobserved during defecation according to the first embodiment of thepresent invention.

FIG. 3(a) is a bottom view of a toilet seat according to the firstembodiment of the present invention, FIG. 3(b) is a front view of thetoilet seat, and FIG. 3(c) is a front view of a toilet bowl, and FIG.3(d) is a side view of the toilet seat.

FIG. 4 is a structure diagram of a color sensing section including animage-capturing camera, showing a light-output area for outputtingillumination light and a light-input area for receiving image-capturinglight, according to the first embodiment of the present invention.

FIG. 5 is a view illustrating a lighting illuminator and a light-outputarea for outputting illumination light according to the first embodimentof the present invention.

FIG. 6 is a structure diagram of an image-capturing camera in which anarea sensor is used as the image-capturing element according to thefirst embodiment of the present invention.

FIG. 7 is a view showing an optical relationship between a single colorsensing section of FIG. 4 and FIG. 6 and feces as the subject, as seenfrom the side direction, according to the first embodiment of thepresent invention.

FIG. 8 is a view showing an optical relationship between a plurality ofcolor sensing sections and feces as the subject, as seen from the toiletseat bottom surface direction, according to the first embodiment of thepresent invention.

FIG. 9 is a structure diagram of an image-capturing camera in which alinear sensor and a cylindrical lens are used as the image-capturingelement according to the second embodiment of the present invention.

FIG. 10 is a structure diagram of a color sensing section including animage-capturing camera, showing the relative positions over time betweenthe light-output area for outputting illumination light, the line ofimage-capturing light to be received by pixels of the linear sensor, andfeces as the subject, according to the second embodiment of the presentinvention.

FIG. 11 is a diagram showing output waveforms over time of the linearsensor according to the second embodiment of the present invention.

FIG. 12(a) is a diagram showing conceptual output waveforms over time ofthe linear sensor when the illumination wavelength is in a wavelengthrange (λ1) where the absorptance in blood is high, according to thethird embodiment of the present invention.

FIG. 12(b) is a diagram showing conceptual output waveforms over time ofthe linear sensor when the illumination wavelength is in a wavelengthrange (λ2) where the absorptance in blood is low, according to the thirdembodiment of the present invention.

FIG. 12(c) is a diagram showing conceptual differential output waveformsover time of the linear sensor between when the illumination wavelengthis in one of two wavelength ranges (λ1 and λ2) and when the illuminationwavelength is in the other wavelength range, according to the thirdembodiment of the present invention.

FIG. 13(a) is a diagram showing conceptual output waveforms over time ofthe linear sensor of the sensing section 3(a) in the layout shown inFIG. 8 when the illumination wavelength is in the wavelength range (λ1)where the absorptance in blood is high, according to the fourthembodiment of the present invention.

FIG. 13(b) is a diagram showing conceptual output waveforms over time ofthe linear sensor of the sensing section 3(b) in the layout shown inFIG. 8 when the illumination wavelength is λ1, according to the fourthembodiment of the present invention.

FIG. 13(c) is a diagram showing conceptual differential output waveformsover time between the linear sensors of the sensing section 3(a) and thesensing section 3(b) in the layout shown in FIG. 8 when the illuminationwavelength is λ1, according to the fourth embodiment of the presentinvention.

FIG. 14(a) is a diagram showing conceptual output waveforms over time ofthe linear sensor when the illumination light is turned ON, according tothe fifth embodiment of the present invention.

FIG. 14(b) is a diagram showing conceptual output waveforms over time ofthe linear sensor when the illumination light is turned OFF, accordingto the fifth embodiment of the present invention.

FIG. 14(c) is a diagram showing conceptual differential output waveformsover time of the linear sensor between when the illumination light isturned ON and when the illumination light is turned OFF, according tothe fifth embodiment of the present invention.

FIG. 15 is a view showing a color indicator section according to theseventh embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

A method for arranging cameras at positions along the toilet seataccording to an embodiment of the present invention, and a method fordetecting occult blood of a feces surface portion based on thearrangement will now be described with reference to the drawings. In thefollowing description, like parts will be denoted by like referencesigns and like process names, and they will be described in detail atfirst, thereafter omitting redundant description of like parts.

Embodiment 1

FIG. 2 and FIG. 3 are views illustrating the first embodiment of thepresent invention, but the concept also applies to other embodiments.

In FIG. 2, 1 denotes a toilet bowl, with a toilet seat 2 providedthereon. A plurality of color sensing sections 3 a and 3 b are providedon the reverse side of the toilet seat. The structure is such thatbefore feces 5 excreted from a body 4 sink into a water-seal portion(not shown) of the toilet bowl 1, the surface of the feces 5 is observedfrom a plurality of directions by means of the color sensing sections 3a and 3 b.

In the figures, broken line portions of the toilet seat 2 correspond tothe end position of the opening of the toilet seat on the inner sidethereof.

The structure of the toilet seat 2 will be described in greater detailwith reference to FIG. 3. FIG. 3(a) shows the configuration of thereverse side (the toilet bowl side) of the toilet seat 2. A plurality ofcolor sensing sections 3 a, 3 b, 3 c and 3 d are arranged on the reverseside of the toilet seat 2. Normally, in order to keep the toilet seat 2clean, a plurality of spacer portions are provided on the reverse sideportion of the toilet seat 2 to give a spacing between the upper portionof the toilet bowl 1 and the toilet seat 2. In FIG. 2 and FIG. 3, thecolor sensing sections 3 a, 3 b, 3 c and 3 d also serve as the spacerportions.

FIG. 3(b) is a front view of the toilet seat 2, and the color sensingsections 3 a, 3 b, 3 c and 3 d, to serve as spacers, are provided on thereverse side of the toilet seat 2. FIG. 3(c) is a front view of thetoilet bowl 1. The toilet seat 2 is arranged in contact with an upperperipheral portion 1′ of the toilet bowl 1 with the color sensingsections 3 a, 3 b, 3 c and 3 d therebetween. FIG. 3(d) is a side view ofthe toilet seat 2.

In the figure, the broken line portions of the toilet seat 2 and thetoilet bowl 1 correspond to the end portion of the opening of the toiletseat and the toilet bowl on the inner side thereof.

The structure of the color sensing section 3 a of the toilet seat 2 willbe described with reference to FIG. 4. The structure is also the samefor the other color sensing sections 3 b, 3 c and 3 d. The color sensingsection 3 a includes, provided inside a housing 6, an image-capturingsystem and an illumination system, wherein the image-capturing systemincludes an image-capturing camera 7, a lens portion 8 of theimage-capturing camera and an optical window 9, and the illuminationsystem includes an illumination section 10 for outputting illuminationlight. A light-output area 11 for illumination light output from theillumination section 10 is denoted by a broken line in FIG. 4, and alight-input area 12 for receiving image-capturing light from the subjectis denoted by a dotted line in FIG. 4. A control section 13 is providedin the housing 6, thereby synchronizing the illumination section 10 andthe image-capturing camera 7 with each other to obtain a captured imagecorresponding to the illumination light.

The illumination section 10 in FIG. 4 may use a white LED, theimage-capturing camera 7 may use a Bayer-type color camera including anarrangement of color filters of the three primary colors (red, blue andgreen), a color camera of such an arrangement that an infrared lightfilter is provided in a portion of the color filter, or a filterconfiguration in which a portion of the color filter is transparentlight.

Ambient light coming from the gap under the toilet seat may be used,while omitting the white LED.

The image-capturing camera may use a black-and-white camera with nocolor filter, and LED illumination sections of three colors (red, blueand green) may be successively illuminated to capture images in a timedivision manner.

As for the detection of the color of feces, the color of feces can beeasily determined using conventional techniques by calculating signallevels for the three colors (red, blue and green) based on the capturedsignals of the three colors, and comparing them with respect to thereference signal level (range) of the color to be determined, as withordinary color cameras.

The control section 13 of FIG. 4 is capable not only of controlling theillumination system and the image-capturing system of the single colorsensing section 3 a, but also of performing a control in cooperationwith the illumination systems and the image-capturing systems of thecolor sensing sections 3 b, 3 c and 3 d.

The structure of the illumination section 10 of FIG. 4 will be describedwith reference to FIG. 5. The illumination section 10 includesilluminators 15 a and 15 b provided on a circuit board 14, and alens-shaped transparent resin 16 is used to align the output directionof the illumination light output from the illuminator (15 a in thefigure). Thus, it is possible to narrow the width of the light-outputarea 11 for outputting illumination light and to increase the intensityof the illumination light.

When LEDs are used as the illuminators 15 a and 15 b in the illuminationsection 10 of FIG. 5, the size of the illuminator is sufficientlysmaller than the size of the lens-shaped transparent resin 16.Therefore, by arranging the illuminators 15 a and 15 b in the vicinityof each other, the light-output areas 11 for the individual illuminatorscan be substantially aligned with each other. Herein, by varying theemission wavelength between the illuminators 15 a and 15 b, it ispossible to obtain the output from each pixel with respect toillumination light of different wavelength ranges.

The structure of the image-capturing camera 7 of FIG. 4 will bedescribed with reference to FIG. 6. In FIG. 6, an area sensor 18 isprovided, as the image-capturing element, on a circuit board (not shown)of an image-capturing camera housing 17, and the area sensor 18corresponds to the lens portion 8 of FIG. 4, with a lens 19 arranged ina lens barrel 20. The image of the subject on the lens 19 forms an imageon pixels (not shown) of the area sensor. The use of the area sensor 18as the image-capturing element is a characteristic of theimage-capturing camera of Embodiment 1.

FIG. 7 is a view showing an optical relationship between the singlecolor sensing section 3 a of FIG. 4 and FIG. 6 and the feces 5 as thesubject, as seen from the side direction, according to the firstembodiment of the present invention. A light-output area 11a forillumination light, denoted by a broken line, output from the colorsensing section 3 a of the toilet seat 2 is reflected on the surface ofthe feces 5 as the subject to be received by the color sensing section 3a as a light-input area 12 a denoted by a dotted line. Inside the colorsensing section 3 a, the image of the subject received via the opticalwindow forms an image on pixels of the area sensor via the lens portion.

FIG. 8 is a view showing an optical relationship between the colorsensing sections 3 a, 3 b, 3 c and 3 d of FIG. 3 and the feces 5 as thesubject, as seen from the toilet seat bottom surface direction,according to the first embodiment of the present invention. Thelight-output area 11 a for illumination light, denoted by a broken line,output from the color sensing section 3 a of the toilet seat 2 isreflected on the surface of the feces 5 as the subject to be received bythe color sensing section 3 a as the light-input area 12 a denoted by adotted line. This similarly applies to the other color sensing sections3 b, 3 c and 3 d, with their light-output areas denoted as 11 b, 11 cand 11 d and their light-input areas as 12 b, 12 c and 12 d.

As shown in FIG. 8, with the light-output areas for outputtingillumination light, denoted as 11 a, 11 b, 11 c and 11 d, the entirecircumference of the feces 5 as the subject is illuminated. Thelight-input areas 12 a, 12 b, 12 c and 12 d for receiving, into thecolor sensing section, the reflected light from the feces 5, denoted bydotted lines, capture the entire circumference of the feces 5 as thesubject with overlap with one another.

In FIG. 8, an occult blood area 25 is partially present on the surfaceof the feces 5. With such an optical system, the occult blood portion 25can be detected in edge portions of the images from the image-capturingcameras of the color sensing sections 3 b and 3 d, as well as by theimage-capturing camera of the color sensing section 3 a. Since theimage-capturing camera is capable of color image-capturing, such anoptical system can determine the presence/absence of blood based on thecolor information of the occult blood area 25 of the feces surface.

In FIG. 5, by varying the wavelength between the illuminators 15 a and15 b, it is possible to improve the accuracy in sensing the occult bloodarea 25 on the surface of the feces 5. That is, the occult blood areacan be irradiated with illumination light of a wavelength range of redand illumination light of a wavelength range of the complementary colorof red (cyan), and it is possible to grasp the characteristic of thecolor of the occult blood area based on the output values of pixelscorresponding to the respective color filters.

Embodiment 2

As the second embodiment of the present invention, a structure in whicha linear sensor is used as the image-capturing element of theimage-capturing camera 7 of the color sensing section will be describedwith reference to FIG. 9. In FIG. 9, a linear sensor 22 is provided, asthe image-capturing element, on a circuit board 21, and with pixels 23on the linear sensor in a linear arrangement, it is possible to obtainlinear images. For the lens of the linear sensor, a cylindrical lens 24is used as the component, of which the lens size in the verticaldirection and that in the horizontal direction are significantlydifferent from each other as shown in FIG. 9.

FIG. 10 shows a diagram showing the structure of the color sensingsection 3 a of the toilet seat 2 and the structure of the color sensingsection including the image-capturing camera according to the secondembodiment of the present invention. FIG. 10 is similar to FIG. 4 andFIG. 7 of Embodiment 1, and the light-output area 11 for illuminationlight output from the illumination section 10 is the same, but FIG. 10is characteristic in that the input light to be input on the pixels in alinear arrangement, of the light-input area 12 from the feces 5 as thesubject to be received by the pixels of the linear sensor, does not havea width and is in a linear shape, as opposed to Embodiment 1. Thelight-input area 12 is denoted as a light-input area line 12′ in FIG. 10and denoted by a one-dot-chain line so as to be distinguished from FIG.7 of Embodiment 1.

FIG. 10 illustrates an optical system of the color sensing section 3 acapable of detecting the occult blood portion 25 of the feces 5 as thesubject. In the figure, the elapse of time during the downward movementof the feces 5 is represented by times t1, t2, t3, t4 and t5. While thelight-input area line 12′ which can be captured by the pixels of thelinear sensor is denoted by a one-dot-chain line, the occult bloodportion 25 of the feces 5 is captured by the linear sensor at time t3.The feces 5 as the subject are not captured at times t1 and t5, and apart of the feces 5 as the subject where the occult blood portion 25 isabsent is captured at times t2 and t4.

The illumination light output from the illumination section 10 and theimage-capturing camera 7 for capturing an image of the subject aresynchronized with each other by means of the control section 13 in thehousing 6, as in FIG. 7, thereby making it similarly possible to obtaina captured image corresponding to the illumination light.

FIG. 11 shows output waveforms of the linear sensor at times t1, t2, t3,t4 and t5 of FIG. 10. At times t1 and t5, when an image of the feces ofthe subject is not being captured, a background output is output. In thefigures, the opposite ends of the pixel output period are represented bythe first pixel output (Pixel 1) and the last pixel output (end pixel),respectively.

In FIG. 11, at times t2 and t4, when an image of the feces 5 of thesubject in an area where the occult blood portion 25 is absent, theillumination light output from the illumination section 10 is reflectedby the surface of the feces 5 of the subject, which is present at ashorter distance than the background, to return to the sensing section.Therefore, as the output waveform, this reflected light component fromthe feces surface (“feces output” in the figures) appears, in additionto the background output, on the light-input area line 12′. The fecesoutput is determined by the reflectivity of the illumination light atthe feces surface and the intensity of the illumination light at thefeces surface portion.

In FIG. 11, at time t3, when an image of the occult blood portion 25 ofthe feces 5 is captured, the illumination light output from theillumination section 10 passes through the occult blood portion 25adhering to the surface of the feces 5 and is reflected by the fecessurface to again pass through the occult blood portion 25 and return tothe sensing section. Therefore, as the output waveform, this fecesoutput of the occult blood portion appears, in addition to thebackground output and the feces output, on the light-input area line12′. The feces output of the occult blood portion is determined by theabsorption coefficient of the illumination light at the occult bloodportion, the reflectivity of the illumination light at the fecessurface, and the intensity of the illumination light at the fecessurface portion. Herein, the absorption coefficient of the illuminationlight at the occult blood portion varies depending on the proportion ofoxygenated hemoglobin in the occult blood portion and the wavelength ofthe illumination light, as shown in FIG. 1.

Embodiment 3

As the third embodiment of the present invention, where a linear sensoris used as the image-capturing element of the image-capturing camera 7of the color sensing section, FIGS. 12(a) and 12(b) show outputwaveforms of a linear sensor at times t1, t2, t3, t4 and t5 of FIG. 10when the wavelength of the illumination light is varied.

Herein, sensing in which the wavelength of the illumination light isvaried in the infrared light region, which is not a visible range, isalso referred to as color sensing.

FIG. 12(a) shows output waveforms of the linear sensor at times t1, t2,t3, t4 and t5 of FIG. 10, when the wavelength of the illumination lightis λ1. The wavelength λ1 of FIG. 12(a) corresponds to a wavelength rangewhere the absorption coefficient of the occult blood portion is large,and corresponds to a visible range of 600 nm or less or a near infraredregion wavelength range of 800 nm or more in FIG. 1.

FIG. 12(b) shows output waveforms of the linear sensor at times t1, t2,t3, t4 and t5 of FIG. 10, when the wavelength of the illumination lightis λ2. The wavelength λ2 of FIG. 12(b) corresponds to a wavelength rangewhere the absorption coefficient of the occult blood portion is small,and corresponds to a wavelength range of around 670 nm in FIG. 1.

FIG. 12(c) shows output waveforms obtained as the difference between theoutput waveforms of the linear sensor at times t1, t2, t3, t4 and t5 ofFIG. 10 when the wavelength of the illumination light is λ2 and thosewhen the wavelength of the illumination light is λ1. It is possible toincrease the detection accuracy by extracting the signal of the occultblood portion utilizing the difference depending on the wavelength ofthe absorption coefficient of the occult blood portion. The signal leveldifference in the absence of occult blood (deoxygenated hemoglobinincreases the absorption, appearing blackish) is adjusted beforehand,including the difference in the sensitivity of the image-capturingelement to the wavelengths λ2 and λ1, and the difference in the lightintensity due to the difference in the wavelength of the illuminationlight. Normally, the adjustment is done in advance before shipping theproduct. Then, when an image of the feces with occult blood is captured,it is possible to accurately extract only the signal of the occult bloodportion as shown in FIG. 12(c).

As shown in FIG. 1, the absorptance of oxygenated hemoglobin rapidlyincreases on the short wavelength side and on the long wavelength side,with the absorptance minimized in a wavelength range of around 670 nm.It is important to observe this portion for the fecal occult bloodreaction.

The absorption spectrum of blood is determined by hemoglobin of redblood, which accounts for about a half the volume of blood, as shown inFIG. 1. There are two types of hemoglobin in blood, i.e., oxygenatedhemoglobin and deoxygenated hemoglobin, and the reflection spectrumvaries depending on the amount of oxygen bound to hemoglobin. The graphis characteristic in that oxygenated hemoglobin has a local minimumpoint of absorption at 670 nm.

The typical blood oxygen saturation is 95% to 98% in the arteries and60% to 80% in the veins. Therefore, when occult blood is adhering to thefeces surface, if the adherent blood is arterial blood, light isreflected by the feces surface without being substantially absorbed inthe wavelength range of 670 nm, thus appearing red. Therefore, it isimportant to make a comparison between 670 nm and other wavelengthranges.

Also when the adherent blood is venous blood, the main component thereofis oxygenated hemoglobin, and there is a tendency that the absorptanceis locally minimized at 670 nm, but the tendency is not as significantas that with arterial blood. Oxygenated hemoglobin and deoxygenatedhemoglobin both have a significant difference in absorptance between awavelength range of 600 nm or less and a 670 nm wavelength range. Asshown in FIG. 1, it is preferred that the wavelength of the illuminationlight is in a range from 600 nm to 800 nm, where there is a significanthemoglobin difference, and is particularly a single wavelength around670 nm, where the half-value width is narrow (20 nm to 140 nm). Using awavelength of 670 nm, there is an about 10 times sensitivity difference,and when deoxygenated hemoglobin is contained, the light absorptioncoefficient is large, resulting in a low sensor output signal level. Onthe other hand, when no deoxygenated hemoglobin is contained, the lightabsorption coefficient is small, resulting in a high sensor outputsignal level. It is possible to determine the presence/absence of occultblood from the sensor output signal level, and it is possible toeffectively give a warning of colorectal cancer and gastrointestinaldiseases.

Embodiment 4

As the fourth embodiment of the present invention, where a linear sensoris used as the image-capturing element of the image-capturing camera 7of the color sensing section, FIGS. 13(a) and 13(b) show outputwaveforms of the linear sensor at times t1, t2, t3, t4 and t5 of FIG.10, when the sensing section position is varied (the sensing sections3(a) and 3(c) of FIG. 8) in the sensing section layout of FIG. 8.

FIG. 13(a) shows output waveforms of the linear sensor of the sensingsection 3(a) at times t1, t2, t3, t4 and t5 of FIG. 10, when thewavelength of the illumination light is λ1. The wavelength λ1 of FIG.13(a) corresponds to a wavelength range where the absorption coefficientof the occult blood portion is large, and corresponds to a wavelengthrange in a visible range of 600 nm or less in FIG. 1.

FIG. 13(b) shows output waveforms of the linear sensor of the sensingsection 3(c) at times t1, t2, t3, t4 and t5 of FIG. 10, also when thewavelength of the illumination light is λ1. The occult blood portion 25cannot be detected by the sensing section 3(c), which does not give thefeces output of the occult blood portion at time t3.

FIG. 13(c) shows output waveforms obtained as the difference between theoutput waveforms of the linear sensor of the sensing section 3(a) andthose of the linear sensor of the sensing section 3(c) at times t1, t2,t3, t4 and t5 of FIG. 10, also when the wavelength of the illuminationlight is λ1. It is possible to increase the accuracy in detecting theoccult blood portion utilizing the difference depending on thepresence/absence of the occult blood portion.

Embodiment 5

As the fifth embodiment of the present invention, where a linear sensoris used as the image-capturing element of the image-capturing camera 7of the color sensing section, FIG. 14(a) shows output waveforms of thelinear sensor at times t1, t2, t3, t4 and t5 of FIG. 10, whenillumination light of the sensing section having a wavelength of λ1 isemitted (ON) in the sensing section (FIG. 3(a)) layout of FIG. 8. Inthis case, illumination due to ambient light is superposed, in additionto the illumination light from the sensing section, deteriorating theaccuracy in giving the feces output of the occult blood portion.

FIG. 14(b) shows output waveforms of the linear sensor at times t1, t2,t3, t4 and t5 of FIG. 10, when the illumination light of the sensingsection is not emitted (OFF). Since the illumination light is notemitted, there is only illumination from ambient light, resulting in aweak lighting intensity and a low output. Since there is onlyillumination from ambient light, the wavelength has a broad wavelengthband, resulting in a poor accuracy in giving the feces output of theoccult blood portion.

FIG. 14(c) shows differential output waveforms of the linear sensor attimes t1, t2, t3, t4 and t5 of FIG. 10 between when the illuminationlight of the sensing section is emitted (ON) and when it is not emitted(OFF). By obtaining the difference from the output when the illuminationlight is not emitted, i.e., when there is only illumination from ambientlight, it is possible to cancel out. This improves the accuracy ingiving the feces output of the occult blood portion.

Embodiment 6

As the sixth embodiment of the present invention, it is possible toincrease the occult blood detection accuracy based on the frequencydistribution of the location where the occult blood portion is detected,by recording output waveforms from a plurality of color sensing sections3 a, 3 b, 3 c and 3 d shown in FIG. 8 every time, and not determiningoccult blood portion information only from one time but checking itagainst the recorded history of the same person. This is based on thefact that a person normally sits in the same direction during defecationand the fact that the feces are unlikely to rotate during the fecesperistaltic movement through the large intestine, so that once an occultblood reaction starts to be observed, the fecal occult blood portion isrepeatedly located in the same direction.

In the sixth embodiment of the present invention, a toilet bowl/toiletseat used by a plurality of persons needs to identify the same person.For this, it is possible to identify the person based on the body weightby adding a pressure sensor (not shown) to the color sensing sections3(a), 3(b), 3(c) and 3(d), as well as by using an input (not shown) madeby the person for each use. Data of deviation between the plurality ofpressure sensors can also be used for identifying the person, and thecolor of feces can be used for identifying the person.

In the first to sixth embodiments of the present invention, it isnecessary not only to identify the same person but also to record andread data for the same person at a point in time after the color sensingsection. For this, a recording means (not shown) may be provided in thecontrol section to store data therein, or a communication means (notshown) may be provided in the control section to send data to a mainserver or a portable information terminal so that the data isrecorded/stored in the main server or the portable information terminal.

Embodiment 7

As the seventh embodiment of the present invention, FIG. 15 shows anindicator section for indicating the color determined by the feces colordetection device. This indicator section is built in the control sectionof the washing device. As for the connection with the color sensingsection, detected color information is transmitted via wire or radio.The washing device section includes a section for controlling thetemperature of the toilet seat, a section for controlling thetemperature of the spray water, and a section for controlling thepressure of the spray water. The color determined by the feces colordetection device can be indicated by lighting LED lamps. This includesan LED that indicates “normal”, and other LEDs for indicating typicalcolors (e.g., white (green), black, red). On the color indicatorsections for these three colors, there is a label prompting the user totake a test at a hospital. It further includes a memory (e.g., an SDcard) section for recording detected color information. This recordeddata may also record the signal levels for red, blue and green so thatthe levels of these colors can be displayed on a personal computer. Thisdata can be submitted to a hospital to improve the test accuracy bytaking time-series data into consideration.

Embodiment 8

Embodiments of the present invention have been described above whilefocusing on the presence/absence of an occult blood portion on the fecessurface to assist in early detection of colorectal cancer. However, themethod for observing the color of the feces surface according to thepresent invention can be used not only to simply determine the occultblood portion, but also to follow changes in the color of the fecessurface for the general health care of the person.

That is, it is believed that the color of feces contains information ofthe digestive system, and not only the red coloring due to colorectalcancer, for example, but also gastric ulcer, duodenal ulcer, andabnormalities of the pancreas, the small intestine and the largeintestine, etc., are correlated to the color of feces. Other than byobtaining data by capturing color images, it is possible to determinethe health state by combining it with the LED emission wavelength of theillumination section, as in the spectral representation of an occultblood reaction.

A deep green color indicates the possibility of a bile stone stuck inthe bile duct, jaundice, pancreatic cancer or liver cancer, a deep blackcoal tar color indicates the possibility of bleeding of the stomach, anda black color is the color of oxidized iron in blood, indicating thepossibility of gastric ulcer, duodenal ulcer or gastric cancer. Blood ismixed in the feces, i.e., hemorrhagic feces, indicates the possibilityof troubles of the large intestine, as well as colorectal cancer.Moreover, bright-red blood indicates the possibility of rectal cancer.

In any of these cases, the color indicator device indicates the colorand prompts the user to take a test at a hospital so that the user willimmediately take a formal test.

A normal color of feces is yellowish brown. Then, the color detectionresults may be recorded and continued observation may take place.

Embodiment 9

Embodiments of the present invention have been described above regardinga system in which a camera is started to continually capture the imageafter a pressure sensor detects a user sitting in place or after a teststart switch is turned ON.

However, continually capturing the image increases the powerconsumption. In view of this, it is possible to detect the motion offeces by using the camera in a low power consumption mode by performinga binning or thinned image-capturing operation in which the number ofoutput pixels is reduced to compare between image signals from differentcapture times. Then, immediately after a motion is detected, animage-capturing operation in the normal capturing mode is performed, andafter the color is detected, the system is turned OFF, thus realizing afeces color detection device capable of an energy saving operation.

Embodiment 10

While individual embodiments of the present invention have beendescribed above, it is understood that each embodiment can be used incombination with others rather than alone.

While the description above is directed to cases where the sensingsections are provided inside the spacer portions on the bottom surfaceof the toilet seat, the sensing sections may be provided other than inthe spacer portions. As for the alternative locations to provide thesensing sections, the sensing sections may be provided on the upper edgeportion of the toilet bowl or may be embedded in the upper portion ofthe toilet bowl.

When an excreting part washing device is built in the toilet seataccording to the present invention shown in FIG. 2, it is possible toaccurately detect the position of the feces through a three-dimensionalimage-capturing operation by using the plurality of sensing sections ofFIG. 8. By controlling the washing direction toward which warm water issprayed, based on the detected position, using a direction controldevice, it is possible to accurately aim at the position to be washed.

INDUSTRIAL APPLICABILITY

As described above, with the feces color detection device of the presentinvention, which observes the color of the feces surface every time theuser defecates, it is possible to detect occult blood on the fecessurface without the user being aware of it, as well as monitoringchanges in the health state. Because it can be implemented with a simplestructure without any extensive structure, it can be used for thepurpose of general health care of a user himself/herself or for testingthe health state, and may also be used as a toilet bowl (toilet seat) ata hospital or installed in a public bathroom, allowing a fecal occultblood reaction to be detected very inexpensively without using anyreagent.

This enables early detection of colorectal cancer, which sits high inthe cancer death rate rankings, thus saving the medical expense andelongating the average life span.

REFERENCE SIGNS LIST

1 Toilet bowl

2 Toilet seat

3 Color sensing section

4 Body

5 Feces

6 Sensing section housing

7 Image-capturing camera

8 Lens portion

9 Optical window

10 Illumination section

11 Light-output area

12 Light-input area

12′ Light-input area line

13 Control section

14 Circuit board for illuminator

15 Illuminator

16 Lens-shaped transparent resin

17 Image-capturing camera housing

18 Area sensor

19 Lens

20 Lens barrel

21 Circuit board for linear sensor

22 Linear sensor

23 Linear sensor pixel

24 Cylindrical lens

25 Occult blood portion

1. A toilet comprising: a toilet bowl, the toilet bowl configured toretain water in a water-seal portion and configured to receive fecesinto the water-seal portion; a toilet seat provided on the toilet bowl;an illumination section for outputting illumination light to fecesbefore the feces sink into the water-seal portion of the toilet bowl,said illumination section having at least two different emissionwavelengths, the illumination section being provided on the toilet seator an upper portion of the toilet bowl; and a linear sensor havinglight-receiving pixels arranged in a linear array, for receivingreflected light generated by reflection of the illumination light at thefeces, the linear sensor being provided on the toilet seat or an upperportion of the toilet bowl.
 2. The toilet according to claim 1, whereinthe at least two different emission wavelengths are selected from thegroup consisting of a red wavelength, an infra-red wavelength, a bluewavelength and a green wavelength.
 3. The toilet according to claim 2,wherein the illumination section comprises a first illuminator and asecond illuminator, and a wavelength of light output from the firstilluminator differs from a wavelength of light output from the secondilluminator.
 4. The toilet according to claim 3, wherein the wavelengthof the light output from the first illuminator is the red wavelength,and the wavelength of the light output from the second illuminator isthe infra-red wavelength.
 5. The toilet according to claim 3, whereinthe first illuminator and second illuminator are successivelyilluminated in a time division manner.
 6. The toilet according to claim3, the first illuminator is arranged in the vicinity of the secondilluminator in the illumination section.
 7. The toilet according toclaim 1, wherein the illumination section is arranged on or over thelinear sensor.
 8. The toilet according to claim 1, further comprising ahousing provided on the toilet seat or an upper portion of the toiletbowl, wherein the illumination section and linear sensor are providedwithin the same housing.
 9. The toilet according to claim 8, wherein thelinear sensor includes a lens in front thereof, and size of the lens ina vertical direction differ from size of the lens in a horizontaldirection.
 10. The toilet according to claim 1, further comprising acolor indicator unit configured to indicate information for feces colordetermined based on the reflected light received by the linear sensor.11. A toilet seat comprising: an illumination section for outputtingillumination light to feces before the feces sink into water-sealportion of toilet bowl, said illumination section having at least twodifferent emission wavelengths; and a linear sensor havinglight-receiving pixels arranged in a linear array, for receivingreflected light generated by reflection of the illumination light at thefeces.
 12. The toilet seat according to claim 11, wherein the at leasttwo different emission wavelengths are selected from the groupconsisting of a red wavelength, an infra-red wavelength, a bluewavelength and a green wavelength.
 13. The toilet seat according toclaim 12, wherein the illumination section comprises a first illuminatorand a second illuminator, and a wavelength of light output from thefirst illuminator differs from a wavelength of light output from thesecond illuminator
 14. The toilet seat according to claim 13, whereinthe wavelength of the light output from the first illuminator is the redwavelength, and the wavelength of the light output from the secondilluminator is the infra-red wavelength.
 15. The toilet seat accordingto claim 13, wherein the first illuminator and second illuminator aresuccessively illuminated in a time division manner.
 16. The toilet seataccording to claim 13, the first illuminator is arranged in the vicinityof the second illuminator in the illumination section.
 17. The toiletseat according to claim 11, wherein the illumination section is arrangedon or over the linear sensor.
 18. The toilet seat according to claim 11,further comprising a housing, wherein the illumination section andlinear sensor are provided within the same housing.
 19. The toilet seataccording to claim 18, wherein the linear sensor includes a lens infront thereof, and size of the lens in a vertical direction differ fromsize of the lens in a horizontal direction.
 20. The toilet seataccording to claim 11, further comprising a color indicator unitconfigured to indicate information for feces color determined based onthe reflected light received by the linear sensor.